/* Copyright (C) 2000 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* 
   Data structures for mysys/my_alloc.c (root memory allocator)
 */

#ifndef _my_alloc_h
#define _my_alloc_h

#define ALLOC_MAX_BLOCK_TO_DROP			4096
#define ALLOC_MAX_BLOCK_USAGE_BEFORE_DROP	10

#ifdef __cplusplus
extern "C" {
#endif

    typedef struct st_used_mem { /* struct for once_alloc (block) */
        struct st_used_mem *next; /* Next block in use */
        unsigned int left; /* memory left in block  */
        unsigned int size; /* size of block */
    } USED_MEM;

    typedef struct st_mem_root {
        USED_MEM *free; /* blocks with free memory in it */
        USED_MEM *used; /* blocks almost without free memory */
        USED_MEM *pre_alloc; /* preallocated block */
        /* if block have less memory it will be put in 'used' list */
        size_t min_malloc;
        size_t block_size; /* initial block size */
        unsigned int block_num; /* allocated blocks counter */
        /* 
           first free block in queue test counter (if it exceed 
           MAX_BLOCK_USAGE_BEFORE_DROP block will be dropped in 'used' list)
         */
        unsigned int first_block_usage;

        void (*error_handler)(void);
    } MEM_ROOT;

#ifdef  __cplusplus
}
#endif

#endif
